1.\" $NetBSD: ctermid.3,v 1.8 2002/02/07 07:00:11 ross Exp $ 2.\" 3.\" Copyright (c) 1990, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)ctermid.3 8.1 (Berkeley) 6/4/93 35.\" 36.Dd June 4, 1993 37.Dt CTERMID 3 38.Os 39.Sh NAME 40.Nm ctermid 41.Nd generate terminal pathname 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.Fd #include \*[Lt]stdio.h\*[Gt] 46.Ft char * 47.Fn ctermid "char *buf" 48.Sh DESCRIPTION 49The 50.Fn ctermid 51function generates a string, that, when used as a pathname, refers to 52the current controlling terminal of the calling process. 53.Pp 54If 55.Ar buf 56is the 57.Dv NULL 58pointer, a pointer to a static area is returned. 59Otherwise, the pathname is copied into the memory referenced by 60.Ar buf . 61The argument 62.Ar buf 63is assumed to point to an array at least 64.Dv L_ctermid 65bytes long (as defined in the include file 66.Aq Pa stdio.h ) . 67.Pp 68The current implementation simply returns 69.Ql /dev/tty . 70.Sh RETURN VALUES 71Upon successful completion, a 72.Pf non- Dv NULL 73pointer is returned. 74Otherwise, a 75.Dv NULL 76pointer is returned and the global variable 77.Va errno 78is set to indicate the error. 79.Sh ERRORS 80The current implementation detects no error conditions. 81.Sh SEE ALSO 82.Xr ttyname 3 83.Sh STANDARDS 84The 85.Fn ctermid 86function conforms to 87.St -p1003.1-90 . 88.Sh BUGS 89By default the 90.Fn ctermid 91function writes all information to an internal static object. 92Subsequent calls to 93.Fn ctermid 94will modify the same object. 95